Cooling fan for vehicle radiator

ABSTRACT

A cooling fan is disclosed to have a hollow hub, a rim spaced around the hollow hub, and a plurality of blades equiangularly spaced around the hollow hub and respectively connected between the hollow hub and the rim, each blade curving from the hollow hub in a positive sloping and then in a negative sloping toward the rim and having a plurality of grooves arranged in parallel on one surface thereof in a curvature corresponding to the profile of the blades.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electric fans and more particularly, to a cooling fan for use in a radiator of a motor vehicle.

2. Description of the Related Art

In a motor vehicle, a cooling fan is mounted on the radiator and driven by a motor to induce currents of air toward the radiator, thereby dissipating heat from the radiator into the outside open air.

FIG. 1 shows a conventional cooling fan for this purpose. According to this design, the cooling fan 12 comprises a plurality blades 14 equiangularly spaced around the hub. The blades 14 commonly have a smooth outer surface. It is well known that the air volume of a cooling fan is determined subject to the cooling fan's diameter and revolving speed, and the power consumption of a cooling fan is directly proportional to the cube root of the revolving speed. Currently, vehicle radiators are made relatively finer than ever. Due to limited installation space, the size of the cooling fan for use with a radiator in a motor vehicle is limited. According to the aforesaid conventional design, the smooth surface blades 14 of the cooling fan 12 cannot induce sufficient air volume to dissipate heat from the radiator efficiently.

Therefore, it is desirable to provide a cooling fan for vehicle radiator that eliminates the aforesaid problem.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a cooling fan for vehicle radiator, which produces a high volume of air during rotation. It is another object of the present invention to provide a cooling fan for vehicle radiator, which dissipates heat from the radiator into the outside open air efficiently.

1. To achieve these and other objects of the present invention, the cooling fan comprises a hollow hub, a rim spaced around the hollow hub, and a plurality of blades equiangularly spaced around the hollow hub and respectively connected between the hollow hub and the rim. The blades curve from the hollow hub toward the rim, each having a plurality of grooves arranged in parallel on one surface thereof in a curvature corresponding to the profile of the blades. Further, the blades curve from the hollow hub in a positive sloping and then in a negative sloping toward the rim.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a cooling fan according to the prior art.

FIG. 2 is an oblique front elevation of a cooling fan according to the present invention.

FIG. 3 is an oblique rear elevation of the cooling fan according to the present invention.

FIG. 4 is a sectional elevation in an enlarged scale of a part of the cooling fan according to the present invention.

FIG. 5 is a schematic drawing showing one installation example of the present invention.

FIG. 6 is a schematic drawing showing another installation example of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 2˜4, a cooling fan 22 in accordance with the present invention is shown comprising a hollow hub 24, a rim 28 arranged around the hollow hub 24, and a plurality of blades 26 equiangularly arranged around the hollow hub 24 and connected between the periphery of the hollow hub 24 and the inside wall of the rim 28. Each blade 26 curves from the hollow hub 24 in a positive sloping and then in a negative sloping toward the rim 28. Further, each blade 26 has a plurality of grooves 30 on one surface thereof. The grooves 30 are curved corresponding to the profile of the blades 26. The grooves 30 enhance the volume of intake flow of air during rotation of the blades 26 because the blades 26 can catch air of relatively lower density when compared to conventional designs.

According to fan affinity laws, the performance of a fan can be calculated by changing the test parameters during rotation of the fan. The change of the test parameters is applicable only to the same type of fans on the same performance curve. The relationship between air volume (air quantity) and air density can be expressed as follows: Q=1/γ^(1/2)

-   -   wherein Q: air volume/air quantity; γ:air density.

According to the aforesaid equation, air volume is indirectly proportional to air density^(−1/2), therefore air volume is relatively increased subject to the decrease of air density. Because the blades 26 can catch air of relatively lower density, the invention can obtain a relatively greater air volume.

Further, the hollow hub 24, the blades 26 and the rim 28 are molded from plastics in integrity, thereby saving the manufacturing cost of the cooling fan 22. According to tests, the cooling fan 22 shows the best performance in catching low density air when the area of the grooves 30 is about one half of the width of the blade 26.

The cooling fan 22 can be installed in the top side of the radiator 32, as shown in FIG. 5. Alternatively, the cooling fan 22 can be installed in the bottom side of the radiator 32, as shown in FIG. 6. When started, the cooling fan 22 induces a big volume of air toward the radiator 32 to dissipate heat from the radiator 32 into the outside open air efficiently.

A prototype of cooling fan has been constructed with the features of FIGS. 2˜4. The cooling fan functions smoothly to provide all of the features discussed earlier.

Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. 

1. A cooling fan comprising a hollow hub, a rim spaced around said hollow hub, and a plurality of blades equiangularly spaced around said hollow hub and respectively connected between said hollow hub and said rim, wherein said blades are curving from said hollow hub toward said rim, each having a plurality of grooves arranged in parallel on one surface thereof in a curvature corresponding to the profile of said blades.
 2. The cooling fan as claimed in claim 1, wherein the grooves of each of said blades occupy one half of the width of the associating blade.
 3. The cooling fan as claimed in claim 1, which is installed in a top side of a radiator of a motor vehicle.
 4. The cooling fan as claimed in claim 1, which is installed in a bottom side of a radiator of a motor vehicle.
 5. The cooling fan as claimed in claim 1, which is coupled to a motor and rotatable by said motor.
 6. The cooling fan as claimed in claim 1, wherein said blades curve from said hollow hub in a positive sloping and then in a negative sloping toward said rim.
 7. The cooling fan as claimed in claim 1, wherein said hollow hub, said rim and said blades are molded from plastics.
 8. The cooling fan as claimed in claim 1, wherein said hollow hub, said rim and said blades are made in integrity. 